About biogas

What biogas is?

Biogas is formed when various microorganisms ”feed” and decompose in an oxygen-free state, i.e. in a biogas reactor. Microbes convert biomass into gas, i.e. fats, carbohydrates and proteins that feed microbes are converted into methane and carbon dioxide. The result of decomposition is methane-containing biogas and digestate containing excellent fertiliser and organic matter. The process is also called anaerobic treatment, biogasification or digestion.

Biogas is a gas mixture containing approximately 40-70% methane, about 30-60% carbon dioxide and, in low concentrations, e.g. sulfur compounds. Biogas is a renewable biofuel and energy source with significant environmental benefits. Biogas is utilised in heat and electricity production and can be refined into biomethane (CBG), a vehicle fuel.

Methane is a powerful greenhouse gas and, when released freely into the atmosphere, 20 to 70 times more potent than carbon dioxide. When the biogas produced in the process is recovered and utilised, greenhouse gases can be significantly reduced. Biogas is found in nature and is formed in wetlands, aquifers of water bodies and in the intestines of animals. There are various technical options for producing biogas when our company’s biogas plant. When the biogas process is managed with high quality, anaerobic treatment reduces the odour nuisance and greenhouse gas emissions of manure and other biodegradable feedstocks, and improves their hygiene in the same process when producing clean energy, i.e. biogas.

Why is biogas produced?

Finland as a country aims for carbon neutrality in the 2030s, so renewable energy production plays a significant role in reducing greenhouse gases and recycling nutrients. The biogas process enables efficient nutrient recycling on farms, self-sufficient energy production, and the processing of biomethane reduces emissions from transport and industry. In addition, Finland aims to increase biogas production to 4 TWh by 2030. Finland’s biogas production has long been around 1 terawatt hour (TWh) for several years. The Finnish Government set the target in 2021 in connection with the budget and climate negotiations in autumn 2021.

Biogas is domestic, renewable and low-emission energy that is a solution for transport, energy production, agriculture and industry. In 2021, biogas was mainly produced from sewage sludge, biowaste and landfill gases, which was utilised for 60% heat production. According to various estimates, Finland’s biogas production potential is approximately 10–25 TWh per year. In 2030, plants in Finland are estimated to have about 4.7 million tonnes of feedstock, about 300,000 tonnes of food industry side streams, about 900,000 tonnes of plant biomass, about 600,000 tonnes of biowaste and just under 600,000 tonnes of sludge. By increasing biogas production, the aim is to reduce carbon dioxide emissions in the transport, agriculture and waste sectors. In addition, the aim is to improve security of supply and increase national energy and nutrient self-sufficiency. Approximately 2.5 TWh of the target will be allocated to road transport.

On-farm biogas production

In Finland, there are currently (12/2023) about 30 farm-specific biogas plants in operation. There are currently 17 plants under construction in Finland, of which 11 are farm-specific biogas plants. In Finland, farms produce approximately 17.1 million tonnes of manure and 1.5 million tonnes of surplus grass, which contain almost 83,000 tonnes of nitrogen and 22,000 tonnes of phosphorus. The biogas potential of farm feedstocks is significant, estimated at approximately 4 terawatt hours (TWh). The calculation does not take into account field biomass cultivated for biogas production, and it has been estimated that they could be produced as biogas for several terawatt hours without hindering feed and food production (Finnish Biocycle and Biogas Association). The farm can utilise slurry, surplus grass, straw and dry manure from production animals in biogas production. Biogas production requires an environmental permit, for which the farm company acquires expert services to streamline the permit process. The benefits of the farm in biogas production are self-sufficient energy production, fertilizer benefit, manure separation in connection with the biogas process and reduction of odour nuisance. The biogas process breaks down most of the nitrogen bound in proteins or mineralises into ammonium nitrogen, which can be more easily utilised by plants. It is possible for the farm to accept external feeds in accordance with the regulations. Starting biogas production requires, among other things, a study of feed volumes, energy consumption, technology and profitability, after which the farm applies for an environmental permit and investment support for the project.

Source: Suomen Biokierto ja Biokaasu ry